The correct answer is 1.1 moles
Answer is: concentration ammonia is higher than concentration of ammonium ion.
Chemical reaction of ammonia in water: NH₃ + H₂O → NH₄⁺ + OH⁻.
Kb(NH₃) = 1,8·10⁻⁵.
c₀(NH₃) = 0,8 mol/L.
c(NH₄⁺) = c(OH⁻) = x.
c(NH₃) = 0,8 mol/L - x.
Kb = c(NH₄⁺) · c(OH⁻) / c(NH₃).
0,000018 = x² / 0,8 mol/L - x.
solve quadratic equation: x = c(NH₄⁺) = 3,79·10⁻³ mol/L.
Answer:
Highest speed: He
Lowest speed: CO2
Explanation:
The rms speed (average speed) of the molecules/atoms in an ideal gas is given by:

where
R is the gas constant
T is the absolute temperature of the gas
M is the molar mass of the gas, which is the mass of the gas per unit mole
From the equation, we see that at equal temperatures, the speed of the molecules in the gas is inversely proportional to the molar mass: the higher the molar mass, the lower the speed, and vice-versa.
In this problem, we have 5 gases:
(CO2) (O2) (He) (N2) (CH4)
Their molar mass is:
CO2: 44 g/mol
O2: 16 g/mol
He: 4 g/mol
N2: 14 g/mol
CH4: 16 g/mol
The gas with lowest molar mass is Helium (He): therefore, this is the gas with greatest average speed.
The gas with highest molar mass is CO2: therefore, this is the gas with lowest average speed.
Get to know first how many moles in the gas:n = pV/RT= (1.013*10^5*750/760) Pa *1.49*10^-3 m^3/(8.314 J/(molK)*298) n = 0.0601 moles.
The combustion energies are 889 kJ/mol (methane) and 2 220 kJ (propane) x = moles methane, y = moles propane
x*889 + y*2220 = 778 x + y = 0.0601----------- x = 0.267784 moles = 0.267784*100/0.0601 = 44.6 % y = 0.243216 moles = 0.243216*100/0.0601 = 55.4 %
When a pot of water sits on a hot stove, the metal pot is
heated, and then transfers its heat to the water. A student claims that
conduction is the only type of heat
transfer occurring. The statement that explains why the student’s idea is
incorrect Conduction cannot occur between two different phases of matter. The answer
is letter A.